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https://www.readbyqxmd.com/read/28092594/adaptive-trajectory-tracking-of-nonholonomic-mobile-robots-using-vision-based-position-and-velocity-estimation
#1
Luyang Li, Yun-Hui Liu, Tianjiao Jiang, Kai Wang, Mu Fang
Despite tremendous efforts made for years, trajectory tracking control (TC) of a nonholonomic mobile robot (NMR) without global positioning system remains an open problem. The major reason is the difficulty to localize the robot by using its onboard sensors only. In this paper, a newly designed adaptive trajectory TC method is proposed for the NMR without its position, orientation, and velocity measurements. The controller is designed on the basis of a novel algorithm to estimate position and velocity of the robot online from visual feedback of an omnidirectional camera...
January 16, 2017: IEEE Transactions on Cybernetics
https://www.readbyqxmd.com/read/28092590/adaptive-neural-synchronization-control-for-bilateral-teleoperation-systems-with-time-delay-and-backlash-like-hysteresis
#2
Huanqing Wang, Peter Xiaoping Liu, Shichao Liu
This paper considers the master and slave synchronization control for bilateral teleoperation systems with time delay and backlash-like hysteresis. Based on radial basis functions neural networks' approximation capabilities, two improved adaptive neural control approaches are developed. By Lyapunov stability analysis, the position and velocity tracking errors are guaranteed to converge to a small neighborhood of the origin. The contributions of this paper can be summarized as follows: 1) by using the matrix norm established using the weight vector of neural networks as the estimated parameters, two novel control schemes are developed and 2) the hysteresis inverse is not required in the proposed controllers...
January 10, 2017: IEEE Transactions on Cybernetics
https://www.readbyqxmd.com/read/28092567/inter-joint-coordination-deficits-revealed-in-the-decomposition-of-endpoint-jerk-during-goal-directed-arm-movement-after-stroke
#3
Jozsef Laczko, Robert Arthur Scheidt, Lucia S Simo, Davide Piovesan
It is well-documented that neurological deficits after stroke can disrupt motor control processes that affect the smoothness of reaching movements. The smoothness of hand trajectories during multi-joint reaching depends on shoulder and elbow joint angular velocities and their successive derivatives as well as on the instantaneous arm configuration and its rate of change. Right-handed survivors of unilateral hemiparetic stroke and neurologically-intact control participants held the handle of a two-joint robot and made horizontal planar reaching movements...
January 16, 2017: IEEE Transactions on Neural Systems and Rehabilitation Engineering
https://www.readbyqxmd.com/read/28092532/improved-shear-wave-group-velocity-estimation-method-based-on-spatiotemporal-peak-and-thresholding-motion-search
#4
Carolina Amador Carrascal, Shigao Chen, Armando Manduca, James F Greenleaf, Matthew Urban
Quantitative ultrasound elastography is increasingly being used in the assessment of chronic liver disease. Many studies have reported ranges of liver shear wave velocities values for healthy individuals and patients with different stages of liver fibrosis. Nonetheless, ongoing efforts exist to stabilize quantitative ultrasound elastography measurements by assessing factors that influence tissue shear wave velocity values, such as food intake, body mass index (BMI), ultrasound scanners, scanning protocols, ultrasound image quality, etc...
January 11, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28092517/transformations-based-on-continuous-piecewise-affine-velocity-fields
#5
Oren Freifeld, Soren Hauberg, Kayhan Batmanghelich, John W Fisher
We propose novel finite-dimensional spaces of well-behaved Rn → Rn transformations. The latter are obtained by (fast and highly-accurate) integration of continuous piecewise-affine velocity fields. The proposed method is simple yet highly expressive, effortlessly handles optional constraints (e.g., volume preservation and/or boundary conditions), and supports convenient modeling choices such as smoothing priors and coarse-to-fine analysis. Importantly, the proposed approach, partly due to its rapid likelihood evaluations and partly due to its other properties, facilitates tractable inference over rich transformation spaces, including using Markov-Chain Monte-Carlo methods...
January 11, 2017: IEEE Transactions on Pattern Analysis and Machine Intelligence
https://www.readbyqxmd.com/read/28092504/wall-shear-rate-measurement-validation-of-a-new-method-through-multiphysics-simulations
#6
Stefano Ricci, Abigail Swillens, Alessandro Ramalli, Patrick Segers, Piero Tortoli
Wall shear stress is known to affect the vessel endothelial function and to be related to important pathologies like the development of atherosclerosis. It is defined as the product of the blood viscosity by the blood velocity gradient at the wall position, i.e., the wall shear rate (WSR). The WSR measurement is particularly challenging in important cardiovascular sites, like the carotid bifurcation, because of the related complex flow configurations characterized by high spatial and temporal gradients, wall movement, and clutter noise...
January 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28092462/adolescent-cardiovascular-functional-and-structural-outcomes-of-growth-trajectories-from-infancy-prospective-community-based-study
#7
Alanna N Hanvey, Fiona K Mensah, Susan A Clifford, Melissa Wake
BACKGROUND: Adult BMI trajectories outperform single BMI measurements as predictors of cardiovascular mortality; however, it is unknown whether this also holds in childhood. We aimed to identify BMI trajectory categories from birth to adolescence, and examine their associations with adolescent cardiovascular function and structure. METHODS: Adolescents from a community-based prospective birth cohort completed 11-16 BMI measurements between birth and adolescence...
January 16, 2017: Childhood Obesity
https://www.readbyqxmd.com/read/28091901/contractility-of-right-ventricular-myocardium-in-male-and-female-rats-during-physiological-and-pathological-hypertrophy
#8
Yu L Protsenko, A A Balakin, D A Kuznetsov, A G Kursanov, R V Lisin, E A Mukhlynina, O N Lookin
Sex differences in the morphogenesis and adaptation of the mechanisms controlling myocardium contractility during physiological and pathological hypertrophy of the right ventricle were demonstrated in mature rats. The study revealed sex-dependent effects of physiological and pathological cardiac hypertrophy on the coefficient of variation of the cardiomyocyte diameter, length-dependent control of the contractile force, and the maximum velocity of isotonic shortening.
January 14, 2017: Bulletin of Experimental Biology and Medicine
https://www.readbyqxmd.com/read/28091872/impact-of-revascularization-of-coronary-chronic-total-occlusion-on-left-ventricular-function-and-electrical-stability-analysis-by-speckle-tracking-echocardiography-and-signal-averaged-electrocardiogram
#9
Yohei Sotomi, Atsunori Okamura, Katsuomi Iwakura, Motoo Date, Hiroyuki Nagai, Tomohiro Yamasaki, Yasushi Koyama, Koichi Inoue, Yasushi Sakata, Kenshi Fujii
The present study aimed to assess the mechanisms of effects of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) from two different aspects: left ventricular (LV) systolic function assessed by two-dimensional speckle tracking echocardiography (2D-STE) and electrical stability evaluated by late potential on signal-averaged electrocardiogram (SAECG). We conducted a prospective observational study with consecutive CTO-PCI patients. 2D-STE and SAECG were performed before PCI, and after 1-day and 3-months of procedure...
January 13, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28091641/effects-of-pomegranate-extract-in-supplementing-gonadotropin-releasing-hormone-therapy-on-idiopathic-central-precocious-puberty-in-chinese-girls-a-randomized-placebo-controlled-double-blind-clinical-trial
#10
Jinsheng Liu, Jiulai Tang
Central precocious puberty (CPP) without organic abnormality is called idiopathic CPP (ICPP). The objective of this trial was to evaluate the effects of pomegranate extract in supplementing gonadotropin-releasing hormone (GnRH) analog therapy on ICPP-affected girls in the Chinese population. 286 girls, diagnosed with ICPP were initially enrolled into this trial, and among them 225 eligible patients were randomized to receive a combinational GnRH analog treatment supplemented with either a placebo or pomegranate extract on a daily basis for a period of 3 months...
January 16, 2017: Food & Function
https://www.readbyqxmd.com/read/28091557/the-same-oculomotor-vermal-purkinje-cells-encode-the-different-kinematics-of-saccades-and-of-smooth-pursuit-eye-movements
#11
Zongpeng Sun, Aleksandra Smilgin, Marc Junker, Peter W Dicke, Peter Thier
Saccades and smooth pursuit eye movements (SPEM) are two types of goal-directed eye movements whose kinematics differ profoundly, a fact that may have contributed to the notion that the underlying cerebellar substrates are separated. However, it is suggested that some Purkinje cells (PCs) in the oculomotor vermis (OMV) of monkey cerebellum may be involved in both saccades and SPEM, a puzzling finding in view of the different kinematic demands of the two types of eye movements. Such 'dual' OMV PCs might be oddities with little if any functional relevance...
January 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28091544/ultrasound-prediction-of-abnormal-infant-development-in-hypertensive-pregnant-women-in-the-second-and-third-trimester
#12
Guofang Shen, Yajuan Huang, Lixin Jiang, Jinghong Gu, Yaxin Wang, Bing Hu
The objective was to assess the sensitivities and accuracies of Doppler ultrasound parameters in the second and third trimester of hypertensive pregnancies in determining perinatal outcomes. 1,054 pregnancies were retrospectively categorized into three groups (healthy pregnancies (HP, n = 988), pregnancies of hypertensive women (HypP, n = 30) and high-risk hypertension pregnancies (HRHypP, n = 36), depending on gestational hypertension as well as fetal birth weights and pregnancy outcomes. Systolic/diastolic ratio (S/D), resistance index (RI), pulsatility index (PI) of the bilateral uterine artery, umbilical artery and vein as well as venous flow velocity data were monitored by Doppler ultrasound...
January 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28090780/a-multi-body-dynamics-study-on-a-weight-drop-test-of-rat-brain-injury
#13
Wenyi Yan, Germain Sossou, Ramesh Rajan
Traumatic brain injury (TBI), induced by impact of an object with the head, is a major health problem worldwide. Rats are a well-established animal analogue for study of TBI and the weight-drop impact-acceleration (WDIA) method is a well-established model in rats for creating diffuse TBI, the most common form of TBI seen in humans. However, little is known of the biomechanics of the WDIA method and, to address this, we have developed a four-degrees-of-freedom multi-body mass-spring-damper model for the WDIA test in rats...
January 16, 2017: Computer Methods in Biomechanics and Biomedical Engineering
https://www.readbyqxmd.com/read/28090766/gas-diffusion-barriers-prepared-by-spatial-atmospheric-pressure-plasma-enhanced-ald
#14
Lukas Hoffmann, Detlef Theirich, Sven Pack, Firat Kocak, Daniel Schlamm, Tim Hasselmann, Henry Fahl, André Räupke, Hassan Gargouri, Thomas Riedl
In this paper we report on aluminum oxide (Al2O3) gas permeation barriers prepared by spatial ALD (SALD) at atmospheric pressure. We compare the growth characteristics and layer properties using trimethylaluminium (TMA) in combination with an Ar/O2 remote atmospheric pressure plasma for different substrate velocities and different temperatures. The resulting Al2O3 films show ultra-low water vapor transmission rates (WVTR) on the order of 10-6 gm-2d-1. In notable contrast, plasma based layers already show good barrier properties at low deposition temperatures (75°C) while water based processes require a growth temperature above 100°C to achieve equally low WVTRs...
January 16, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28090505/usefulness-of-intraopertive-ultrasonography-during-directional-atherectomy-using-silverhawk-turbohawk-system
#15
Yoong-Seok Park, Seon-Hee Heo, Dong-Ho Hyun, Young-Soo Do, Hong-Suk Park, Kwang-Bo Park, Young-Wook Kim, Yang-Jin Park, Chul-Hyung Lee, Dong-Ik Kim
PURPOSE: Directional atherectomy (DA) was introduced for the management of infrainguinal arterial stenosis or occlusive lesions. The procedure success rate in the DEFINITIVE LE study was determined using radiologic imaging. The aim of our study was to determine the usefulness of intraoperative ultrasonography (USG) during DA for evaluating the early results of this procedure. METHODS: Patients who underwent DA from January to December 2014 were reviewed retrospectively...
January 2017: Annals of Surgical Treatment and Research
https://www.readbyqxmd.com/read/28090292/a-new-look-at-bronchopulmonary-dysplasia-postcapillary-pathophysiology-and-cardiac-dysfunction
#16
Arvind Sehgal, Andra Malikiwi, Eldho Paul, Kenneth Tan, Samuel Menahem
Pulmonary hypertension (PH) and right ventricular function are the focus of cardiovascular effects of bronchopulmonary dysplasia (BPD). We assessed cardiac indexes reflecting systemic afterload and pulmonary venous back pressure as pathophysiologic factors. Cardiac parameters were measured by conventional echocardiography in 20 preterm infants with severe BPD and compared with those of 10 preterm infants with no BPD and 20 healthy term infants. In infants with severe BPD, PH was noted in 5 (25%) by tricuspid regurgitation Doppler jet ≥2...
December 2016: Pulmonary Circulation
https://www.readbyqxmd.com/read/28090259/prevalence-of-pulmonary-arterial-hypertension-in-korean-adult-patients-with-systemic-sclerosis-result-of-a-pilot-echocardiographic-screening-study
#17
Su-Jin Yoo, Jae-Hyeong Park, Yunseon Park, Jae-Hwan Lee, Byung-Joo Sun, Jinhyun Kim, In Seol Yoo, Seung Cheol Shim, Seong Wook Kang
BACKGROUND: Pulmonary arterial hypertension (PAH) is a major cause of morbidity and mortality among patients with systemic sclerosis (SSc). Early detection and prompt treatment of PAH associated with SSc (SSc-PAH) result in better prognosis. We conducted echocardiographic study to presume the prevalence of PAH in Korean adult SSc patients and to diagnose SSc-PAH in their early stages with right heart catheterization (RHC). METHODS: We performed free of charge echocardiographic study including 37 adult SSc patients at the Chungnam National University Hospital...
December 2016: Journal of Cardiovascular Ultrasound
https://www.readbyqxmd.com/read/28090144/maximal-power-training-induced-different-improvement-in-throwing-velocity-and-muscle-strength-according-to-playing-positions-in-elite-male-handball-players
#18
M Cherif, H Chtourou, N Souissi, A Aouidet, K Chamari
This study was designed to assess the effect of strength and power training on throwing velocity and muscle strength in handball players according to their playing positions. Twenty-two male handball players were assigned to either an experimental group (n=11) or a control group (n=11) (age: 22.1 ± 3.0 years). They were asked to complete (i) the ball throwing velocity test and (ii) the one-repetition maximum (1-RM) tests for the half-back squat, the pull-over, the bench press, the developed neck, and the print exercises before and after 12 weeks of maximal power training...
December 2016: Biology of Sport
https://www.readbyqxmd.com/read/28089456/protective-effects-of-exercise-training-on-endothelial-dysfunction-induced-by-total-sleep-deprivation-in-healthy-subjects
#19
Fabien Sauvet, Pierrick J Arnal, Pierre Emmanuel Tardo-Dino, Catherine Drogou, Pascal Van Beers, Clément Bougard, Arnaud Rabat, Garance Dispersyn, Alexandra Malgoyre, Damien Leger, Danielle Gomez-Merino, Mounir Chennaoui
BACKGROUND: Sleep loss is a risk factor for cardiovascular events mediated through endothelial dysfunction. AIMS: To determine if 7weeks of exercise training can limit cardiovascular dysfunction induced by total sleep deprivation (TSD) in healthy young men. METHODS: 16 subjects were examined during 40-h TSD, both before and after 7weeks of interval exercise training. Vasodilatation induced by ACh, insulin and heat (42°C) and pulse wave velocity (PWV), blood pressure and heart rate (HR) were assessed before TSD (controlday), during TSD, and after one night of sleep recovery...
January 5, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28089275/microfluidic-membrane-suppressor-module-design-and-evaluation-for-capillary-ion-chromatography
#20
Sam Wouters, Cees Bruggink, Yury Agroskin, Christopher Pohl, Sebastiaan Eeltink
A microfluidic ion-suppression module for use in ion-exchange chromatography has been developed and evaluated. The device consists of an ion-exchange membrane clamped between two polymer chips featuring a 200×100μm (width×depth) eluent channel (l=60mm), and a 300×150μm regenerant channel (60mm), respectively. The suppression efficacy using a Nafion membrane was compared with that of a styrene-sulfonate grafted fluorinated ethylene propylene (FEP) membrane. The latter was found to outperform Nafion in terms of lowest attainable background signal (suppression efficacy) and dynamic suppression range...
December 29, 2016: Journal of Chromatography. A
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